Electric meter



BEST AVAILABLE COP.-

1 (No Model.) 7 Sheets-Sheet 1.

T. DUNCAN.

ELECTRIC METER.

, 1 Io.550,8Z3. Patentd Dec. 3, 1895.

AND RECORDING WATT HOUR METER moo BEST AVAILABLE COP.

(No Model.) 7 7 Sheets-Sheet 2. T. DUNCAN.-

v 'ELEC'IRIGMBTER. No. 550,828Q Patented 1160.3, 1895.

Fig.2-

ab m BESTAVAILABLE coPx (No Model.)

ELECTRIC METER.

No 550,823. Patented 1350.6, 1895.

I Qbtozmugs 7 Sheets-Sheet 3. T. DUNCAN. I

BEST AVAILABLE COP;

4T.DUN0AN. ELECTRIC METER.

(No Model.)

,Paltented Dec. 3

Fig.1!

49W 5 144mm to;

o. I ayw BESTAVAILABL'E com Nd Model.) 7 Sheets-Sheet 5.

T.DUNCAN.

ELECTRIC METER.

Patented Dec. 3,1895.

I Wibweooea (No Model.)

BEST AVAlLABLE can 7 Sneak T. DUNCAN.

ELECTRIC METER.

Patented Dec. 3, 1895.

Sheet 6.

W M gwvehtoi 3 5313%; abllozwuss BEST ILABLE com mumoaemi 'Shts-heet 7.

' T. "DUNCAN ELECTRIC METER. 4. No 550,823. LPatented Dec. 3,1895.

- i Swuemboz $514 Gamma 'rnoivi/is'. nimonn; or lro m mm; INIHANA-I Ens-crate ,M ET'ERQ srnczrrcn'rxon f'gmin m of Letters Patent n 550,823, dii-ted, December 3. .18 5.

To (ZZZ whom, itfimty (mm-m Be it known'that I, 'lno'nns I) uneasy-a citizenof the-United States," residing atltort \Vayne,'i'n the count y'of Allen, in the Stateof reference be'iig had. to the accompanying Indiana, have invented certain new and useful- Improvements in Eleetricity-Meteisg and I do hereby declare that thefollowing is a-full, clean-,and exact description of i re. invent-ion,

' whichwill ennble'others skilled'in the art to which it appertain's ,to make and use the same,

drawings. whieh form part of this specificationgff My iila ention relates to that class ofmetcis known as integrating and. recording energ or watt-hour meters, having a commutator for rectifying the armature-cu-rrentand ere crting a torque proportional to the energy passing througlrit, and has for its objectthe following improvements: first, an armature so designed that it is easy to construct, as-

sen1ble,'ins pect, and repair; second, a'coinnmtator and brushes that do not tarnish or become black by'exposure tothe air, but remain bright'and in aperfeetcondition; third,

a proportioning of the winding and form of.

the field-coils and armature, so as to cause the meter to give an absolutely-correct record of the energy passing through it, making no difference whet-herit. reads on direct or alternating current circuits; fourth, the method of preventing deterioration in strength of the magnets employed to produce the necessary brake force by shielding them from .the in- \villbe more fully described hereinafter in detail. l

In the neeompimying drawings, Figurc'l is a front elevation of the meter complete.

2 is a front elevation in section, showing the sition of the-d rig-magnets and the shieldng-eup, also the construction of the field-coils and armature. Fig. 3 is aplan of the motive part of the apparatus, theshielding-cover 16,

and the outline of the base 48. i Fig. 4 shows the construction of the armature, in which the upper half is for showing the mode of wind- Application an; mm, 12 95. Serialh'o.55d,165. Nomodeln 1 Fig.

' (imam;

ing and 1lie .loiver. a section of the finished winding. Fig; 5 serves to give an idea of the complete winding oi the armature with its necessary commutator connections, while Fig. 6 shows aside View of same with the bandor tie thread in place to keep the armature-to gether. Fig; 7 is a plan viewfiniseetion, of

,t-he drag or'brake part of the meterjshowingr the relative positions'of the magnets-and dislu 'Figs; 8, 9, 10, and 11 represent the several 7 views of the armature-spidersandthcirloeation upon the spindle or shaft: In Figslxili,

13, 14, 15,16, and 17 areshown the various ways of connecting the meter into' direct and alternating current circuits of distribution.

Figs. 18, 19, 20, and 21 are plain views-of the retarding partof the meter, showing 'the. diffcrent ways of placing or using the magnets anddisk'. Figs. 22, 23, and 28 are elevgrtion views of'the m'ag nei-s, said Figsflfl and 23 alsoshoiving the location of the dish between their poles. In Figs. -24, 25, 26-, -7, 29, '30, 31', 3'2, 33, 34, 35;- 36, and- 37 are shown the :various parts constituting the construction of fthe armatrecover. A

In the foregoing figures siniila 1 s refer to'similar parts, and in whicl dis h series or field-coils connected by 37-h ej workcircuit, as shown in Fig. 3.

. The coilsniay be connected either in series or multiple, depending upon the desired carrying capacity. In Figs. 1, 2, and 3 they'are shown in series, having their inner terminals joined together by a'clamp 38, Fig.- 3, :while their outer terminals are rigidly connectedby 37 to the outside. binding-posts .14, which connect them with the circuitwires. I'n. winding these field-coils I have experimentally demonstrated that when woundso that their cross-sect-ion'is' square in formtliatis, having sides equal 'in iengtlnas shown in Figs. 2

, and 3-the results'obtained are greatly-in advance of; any yet obtained by any other form. By such a-construction the resistance. the magnetic circuit is reduced to the verylowest possible amount, thereby insuriuga greater density of flux than qtherwise could be obtaiued with a given number of turns and current. I further find that this form of constrnetion is ideal when the entire field envelops the armature, so'that their ends are flush or of the same width, as shown in the loo ' main source of supply and plan view, Fig. 3, where -is the armature. v In these drawings the space between the fieldcoils '9 is shown to be to that of one of the coils; but better results are obtained by making this space smaller and maintaining the form specified when the construction of the meter permits. For ins stance, in a meter not provided with a commutator this space may be made much'smaller, or just large enough 'to allow the shaft to rotate. Besides reducing the magnetic resistance it also reduces the 6 R. lossby .being able to do the same amount of'w'ork withless turns rid length of wire ill'tll coils. Another feature of this fornrof coil is that itpro duces a better starting torque, thereby doing away entirely with a special coil on small meters inserted in shunt across the mains and acting in conjunction with the series coil to give the necessary starting torque to overcome the friction of the bearings of the meter. The coils are connected in series inthe produce a field whosestrength varies with theeurrent flowing. They surround or envelop the armatum 10, which also po'sscsscs many novel features of construction. The armature beingconriectcd in shunt to the mains in series with a resistance gives a field-proportional to the eleetromotive force at its terminals. Hence the torque is equal to the product of the two forces or fields actingupon each other.

in order that thou-ate or rotation maybe in exact raitio' to the energy passing through the meter, the torque resulting from the forces set up by the series or current field and the shout orvolt field must be opposed in'some man ner, otherwise the resulting speed would be an accelerating one. This opposition offeredtto the rotation of the motor be governed by a force which varlesin the same manner as does the torque of the motor itself, as follows:

Since the turning movement of the motor varies as the energy, the opposition or drag must also vary as the energy or torque, which is secured by a Foucault-current drag, consisting of anictallie disk rotated between the poles of one or more magnets. i

In constructing the armature I employ a hollow ring or cylinder, as shown in Fig. 29,

'hich consistsof two rings of wood or other suitable material and of different diameters, Figs. .34. and 26, and in section in Figs. 25

and 27, held together at the top and bottom by anotherflat ring i5 in'Fig. 30. A section of this hollow cylinder is given in Fig. 31. To facilitate windin g1 saw the cylinder through the center in the direction of and with the axis, as'shown in Fig. 4, By so doing the small-armature-coil can bev wound upon a separatc'fin-mcr and then slipped on the hollow core in the manner shown in Fig. 4, separating them with the small rectangularshapcd collars 4i, Fig. 34. I have also, put these collarsiu position by gluing them to the hollow core and winding by hand the coils of a widt-habout equal employed degree, of success.

m ust also 7 t' BEST AVAILABLE com into position. \Vherc the ends butt together, I employ the fiat pieces 39, Fig. 32, which are provided with a semicircular groove, through which fits and passes the screw 46, Fig. 10. This screw is for fastening-the top and bottom spiders 40 together, as shown in section in Fig. 2. The top and bottom parts of the collars 4'2, uponi vhich these spiders rest are, cut away, so as to prevent the spider-arm from being too high, making it normally even or flush with the top of the armature-coils, as shown. These collars 42 are represented in two views by Figs. 36 and 37, respectively.

' When these two halves are brought together and the spiders put into position and screwed fast, the whole is bound around the outside with thread to keep it in arigid state, as shown by the two windings or bands 13 in Fig. (3.

of repair, something to be appreciated by all users of commntate'd motor-meters. The armature is then mounted on a 'spindle21, which also carries the aluminum disk 13, the locking-hub 2i, and the meshes into a suitable worm-wheel and drives the registering-train2, which reads in watt or horse-power hours. This spindle also carrics a commutator of aluminum 6, which forms another of the. elements of myinvcntion.

For years the users of meters having commutators have been given an endless amount of trouble in various ways. It was thought that silver was the only metal that could be to make commutators, and in fact wasthe only one that was productive of a fair However, mentally demonstrated that aluminum is very superior to silver for this purpose in many ways. The drawback attending a commutator made from'silver is in its becoming tarnished and black. This I find to be more marked and troublesome when the meters are 'used in localities where natural gas is employed, due, no doubt, to phur in greater or less quantities. have never seen a meter-in service with a silver commutator for vtwo monthsuntil it wohld be badly tarnished and in many cases quite black. Vv'hen a commutator of aluminum is'cuiployed, this the presence of sultarn'ishing and troublesome effect is wholly eliminated.

I have also employed aluminum alloyed with another metal or metals, making it easier to worlc'by making it harder, with equally good results;

For connecting the armature-termina-ls to the commutator I plate with copper the lower extremities of the commutator, thereby perto take apart in case In fact, I.

a period of more than worm 20, which I have experimitt-ing their being easily soldered to the wires.5.

The current traversing the commutator is small, there being a large resistance 8,.in series wit-h it, which is wound upon a card and slipped down between the two insulating blocks 12 in slots provided for that purpose,

and shown in the plan view, Fig. The

S5. c u rrent the lines of magnetism stand outfrom t-atoi' (hand resistance 8.

' The clamps 34," holding said coils, are held in nec'ted together with a wire 11 in order tocomplete the circuit. The series coils are held upon the c'ross plate or bar 33,which is cast in one piece with the arched support positioh by the screws 35.- The spindle 21m "held yertieally'between the upper bearingl!) and-the lower jeweled bearing 26'. --This lower bearing, .as seen, consists of a threaded post 23, having a portion of its center drilledout, to admit the spring 27, on 'top of whichrests' thejeweland itssetting 26. This jconstrnetiona-llowsfthe meter-to be used or handled without the constant dread of breaking the jewel, as the spiral spring takes lip any sud-'- derr'or dang'ei ous jar, thereby protecting it "-'frorn being broken or damagedby the shaftpo int.- Then this poster bearin" 29 is ad justed; to'the'prope'r height','it is secured by -a' jani-iiiit it is desiredat anytime to handle or 'reino've the" meterQor in cases of transportation it is necessary that the" spinf dle-p'ointbe raised upoutp'f the jeweled bearing, this can be done yerygefieetivelyb raising'the thumb-nut 25, which is'provided on top with a'pointe d extension that fits into ""the circular grooves upon'the lowehside of,

the'hnb-Qt. 4

Figs.l1, 2,- a'nd'3 show the several views of my improved method of prot e'ctingjthe-draga magnets 22 from becoming weak by being.

" subjected .to external magnetism. "This is particularly noticeable when the meter 'is' employed ,to measure the energy on' 'altern at-- ing current eircuitsby reaso' ,otithe lines of alternating magnetism e ail mg 1 W t e v t em by the sudden reversals which they'are snbjecte'd' towhcn placed within an alternating field; I

have also known of. cases'where the magnets were weakened upon 'di rect currentcircuit in'two ways: first, by'be-ing always in'a position. where their polaritywasopposed by the field produced by the series coils, and,.second,

by suddenly changing the intensity of the magnetic flux of the field-coils-sueh, for instance, as when all the lights would be turned on ez-oft atone ti me, or by accidentally opening the circuit, or when a fuse would blow. This can very easily be accounted for by assuming that the time the field-coils are traversed by .a

the axis of the coils, completing their circuit int-he same manner as those emanating from a permanent magnet; but as soon as the current in the series coils is altered there is also;

' a corresponding change in the intensity of ehan eiu the strength of the magnets, Ihave magnetism, .which natura'llyhas a detrimental influence upon the strength of the magnets, being much more marked if the circuit" he accidentally opened or closed when loaded. Therefore, with the object of preventing this The inner .trminalsbf the meterIa-re eon am ified-the fniuiea herein shown; fwhich the magnets-and disk. 3 This 'takcs u'p'any and ail of the stray lines o"n1agnetisi n'a rid conducts them from 'side'to side, which we n-'- otherwise be taken up by the magnets-thaw selves. *llnothefadyantajge of. this form "of: hood is that it renders that part of the ni'c't'e'l absolutely dust-proof and prevents the" err trance of insects. This hood consists oftwo' castings 1(3 arm da-boss 1-5, which fit tog'etlier along the line orsnrfaee shownb'y the seetional View in Fig.2 andare serewed 'ihte posit-ion upon the base by'the four screws 17,

g the front half of thishood is removed for the pi' rposeof'lowering the check or supporting ,i30,.-:Whi($h hold them in position. This means necessary speed has approximatelybeen obbeing able to adjust the rate of rotation to gizingfield coils of the-meter, by havingtheirmagnets at"right angles to the direction of 'imity to the revolublc disk in any of the sev-' cral ways'shown i n.Figs'. 18, 19,20, .21, 2;, and 23,the latter showing thepolarity of side of the disk for from short-circuiting. i Y

I also claim the form of magnets herein and magnetized, besides being least affected by external "fields. lts poles are located at a age.

may be used in places where external fields ing influenced by them and made to giye erroneous indications or records.

myself'solely to the use of the inverted cup or bowl of iron shownjn these drawings, but

'tai ned'by changing the amount of resistancein series with'thearmature, as it admits of' II 00 the-very minutest-degree-of accuracy.

My invention further 'consistsin the post-*- tion-of the magnets; as related-to the; energ na-gnetic flux operating at right-angles to: each other.- \Vhen the drag dnagnets-are- 'fplaced in'this'positioml have found that the effect of the series coils upon' them is eliinie I hated, thereby-showing that when the lines -of force from the field-eoils pass or cut the- Ido not Wish to be understood as limiting consist-s of'the ihond'r 'steel hdod 16, core 113g A L one- :being at each comer- 18. Then the me ter is plac'edfin positionjand rcady to start, I

their flux thatlit-tle .or no reversal takes place. The magnets may be placed in proxthese magnets to be t e same upon the same reventingtheir fields 1 l 10 shown, which I find to be Very easily made I point farthest removed from its neutral lineor yoke, thereby insurin g freedom from leaks \Vith this combinationof improve-- ments in the retarding mechanism, the meter of magnetism are present without fear of be-:

, claim the'u seb f improvement I find to; fully satisfy the pres;

ent requirements and demands of centralstation men and consumers in general in having the following-points of merit:

First, It follows an absolutely straight line law by having the form or shape of the fieldcoils as herein described and of such dimeu-- sions and relations to the diameter of the armature that a correct record upon any load from-unity to maximum is obtained.

Second. It is provided with a commutator and brushes that do not become tarnished and black a few weeks after they are installed and do not cost as much as silver, from which nearly all commutators upon the market at the present time are made. The commutator and brushes are also capable of being used in the presence of. gases that would prove detriment al'in a very shortspace of timeto others made of silver. Further, they do not show the effects of sparking as readily as when silver or any of the other non-oxidizing metals are used.. I

Third. Its armature islight, durable, easily made, assembled, and particularly easy to inspect and repair.

Fourth. The retarding device employed is free from the influence of external fields of magnetism, thereby insuring accuracy of registration by the permanent magnets being protected, so that they will retain their magnetism longer than any others now found in use.

Fifth. It may be employed upon direct or alternating current circuits with equal accuracy and without making any special calibration for either current.

In assembling the meter thecast arch 3 is secured to the base" 48with the screws-31. The said base is provided with the lugs -t7 for fastening it to its support, also a hole 3.6

for locking the cover.

In screwing the magnets upon the bosses provided for them they are first set into the clamps 32, which are licld in position upon said bosses by the screw 80. The clamps, however, could. be dispensed with by having the screws enter the bottom limb of the magnet itself; but it is found somewhat diflicult to properly harden or temper tungsten-steel magnets with holes in them without cracking them.

Fig. 12 is the diagram of a meter without an y auxiliary field-winding, such as small meters whose speed is highrnough upon mim- Figs. 18, 19,

BEST AVAILABLE COP.

mum load; and does not require any extra torque. Fig. 13'shows in series with thes'armature small coils 49, used-in conjunction with each of the series coils 9, for the purpose of helping to start large meters upon small loads. The work-circuits in these views are represented by number 51, while number 50 is the generator.

- Fig. It shows the shunt-whirling ti), wound directly upon the outside of the series coil 9, while Fig. 15 shows only one shunt-coil 49, placed within the said series coil 9. This further. shows the-method of connecting the meter into a three-wire system of distribu- .tion. v

Fig. 16 shows the manner in which the necessary connections are made for measuring the total energy or output from .a central station, in which is employed a transformer consisting of a primary coil 54 and secondary 53. The secondary terminals of the transformer are connected to the armatureIO through the resistance 8 and shunt-coil 49. The totalenergy in this arrangement will be e'qual to the resulting speedor indications multiplied by the ratio of transformation between the primary and the secondary feeding the armature. The transformer 52 is connected to the primary mains and represents the load or energy being consumed and passing through the The-line 56 is connected beyond the meter. series coil of themcters in order that the current required tomagnetize the iron core of the transformer will pass through them, thereby producing an initial fielder torqueto help overcome the friction of the meter. If this method be applied to large buildings,v (where it would require too ,large an outlay to pro vide all the circuits with a meter each,) by simply inserting a meteri'n the primary which feeds all the transformers, the wire 56 would have to be connected tothe other side of the field-coils, as shown by since the magnetizing-current of the sore ral transformers might be enough to cause the meter to run when no lamps were in use upon the secondaries, This motion would be all right in the first cas e-viz., that of measuri n'g the total output of a central station-but in the lattercase the energy consumed as magnetizing-current in the tranformers must be borne by the producers or central-static n com-' pany themselves. Hence the meter in this case must move only at times when thereetr'e lamps in use.

Fig. 17 shows two meters connected into the two sides or circuits of a three-wire-transformer system.

Fig. 28 shows the iorm of magnet used in 20, and-21.

Fig. 29 shows the hollow cylinder before it is cut or sawed through, as shown in section in Fig. 31.

What I claim is-- 1. In an electric meter, a magnetic medium or shield interposed. between the drag orv damping magnets and the field coils or other the dotted line 55,.

and for the purpose described.

BEeTAvAnAeLE COP.

external fields or source of magnetism, adapted to receive the stray lines :of magnetism from the said field' coils or other external source, and thereby protect the said magnets from the effects of external magnetism, as

2." The combination in an electric meter, of a field coil or coils whose sides are rectangular in cross section with sides of equal length, for the purpose specified, an'armature'of suitable construction and rcvoluble within the mag-' nctic field established by said coils, and whose diameter is equal to the axial length ofthe said field coils, a' commutator of aluminum,

an integrating mechanism, a retarding device, and vertical. spindle carrying the said Disclaimer in' Letters Patent No. 550,823

armature, commutator, and moving elements of the retarding device, all substantially as described,

In an electric meter,- the combination of the vertical, externally threaded post 29 re- .movably mounted by a screw threaded con nection upon a suitable 1;.158 or support for the purpose specified, the spiral spring 27 loosely mounted in said post as described, and the, metallic piece 26 arranged in said post, as shown, to suppor the jewel, all substantially- -as described.

4. The combination in an electric meter, of a retarding mechanism consisting of an aluminum disk, traversing the field or fields pro dnced by one or more permanent magnets having their like poles upon the same side of said disk, and a magnetic shield: as and for the purpose herein set forth;

5. The combination inan electric energy meter, of a retarding mechanism, consisting of a metallic disk mounted upon a spindle and revoluble therewith, a multiplicity of magnets whose fields are traveled by said disk, and a hood or -;cther suitable form of;

magnetic material for shielding the drag magpany, assignee.

' Enters its disclaimer- .following words, to wit: or other external Gazette, December 18, 1906.]

DISCLAIMER. 5O,S23.Th0'mas Duncan, Fort Wayne, Indiana. METERS. v

DecemberB. 1895. Disclaimer filed December 13; 1906,12 General Electric Comnets from external magnetic fields, said hood being secured at suitablepoints'upon the base of the meter as set forth. r

6. The combination in an electricity meter of a work or retarding mechanism, consisting of a closed circuit, orconductor moving in close proximity to one-or more permanent magnets which devetcpgr generate Foucault or eddy current in said closed conductor, and

' a shield of magnetic metal interposed between said retarding mechanism and the external source of magnetism to be guarded against,

said shield being divided into two parts to facilitate construction and having a raised portion .or boss at its center through which the spindle passes asand for the purpose set forth.

7. The combination'with the motive part of an electric meter, of an armature consisting of a'. hollow wooden or hard rubber ring or cylinder, upon which are placed the coils, said cylinder orring being divided into two pieces and butting together in the manner shown as and for the purpose set forth.

8. In an electricity.meter,thc combination with a motor, and integrating or indicating mechanism, of a retarding deviceconsisting of a movable aluminum or copper disk or cylinder, being cut in its mot-ionbythe magnetisnrof a plurality of magnets,-having-their field approaching a right angle to the axis of the external magnetic field,- from which they are intended to be shielded, and an iron or other suitable protector' 'of convenient form .-for shieldingsaid me gi ts, as and for the purpose set forth. 1 J

Signed by me, at Fort Wayne,Allen county, State of Indiana, this 20th day of May, A. l).

Patent dated To that part of claim 1 in the specification of said Letters Patent that isin the I fields or source of magnetism. -[0fiicwl A I I I Patent daiaed ,by Geheral Electric Com- DISCLAIMER.

Dzmcgm, Fort vvayne, Indiana.. EIi'EQBTBiG METERS. December 3. 1895. Disclaimr filed December 1906 To that part3 of claim 1 in the specificatioh of said Letters Patent that isin the following words, to wit: or other external fields or source of magnetism. [Ofliq'al M, w a .m s e .m a n c n m m w a T .a m Va 9. w M 2 Llu 8 P n O E 5 mwwammg Es 225 Gazette, December 18, 1906.] 

